Preheat the oven to 375°F. Line 2 large baking sheets with parchment paper.

Combine chocolate and butter in a heat-safe bowl and melt in the microwave in short bursts with frequent stirring until completely melted, smooth and glossy. Set aside.

Place eggs and sugar in a medium bowl and whisk for 2-3 minutes until pale and thickened.

Add slightly warm chocolate mixture and fold it in until evenly blended.

Sift together corn starch, cocoa, baking powder and salt in a small bowl and blend well. Stir it into the chocolate mixture. Fold in chocolate chips.

Cover the bowl and set aside for 10 minutes. If in a hot environment, refrigerate for just 5 minutes until the batter is thick and fudge-like.

Scoop about 1 ½ tablespoons of the fudgy batter onto prepared baking sheets.

Turn the oven down to 350°F and bake for 8-11 minutes until shiny and crackled on top and set around the edges.

Let cookies cool completely on trays before transferring to a cooling rack.